Lead zirconate titanate high-speed electro-optical modulator based on heterogeneous integrated waveguide and preparation method of lead zirconate titanate high-speed electro-optical modulator

Abstract

The invention discloses a lead zirconate titanate high-speed electro-optical modulator based on a heterogeneous integrated waveguide and a preparation method thereof, and belongs to the technical field of planar optical waveguide optical modulators and preparation thereof. The lead zirconate titanate solar cell is composed of a silicon substrate, a silicon dioxide oxide layer, an unetched lead zirconate titanate flat plate core layer, a polymer spacing layer, discrete electrodes and a polymer upper cladding layer in sequence. The polymer spacing layer and the polymer upper cladding layer are made of the same material. According to the invention, the lead zirconate titanate film is used as the waveguide core layer, the polymer spacing layer is directly spin-coated on the lead zirconate titanate film, etching of lead zirconate titanate is not needed, and the light field is limited in the waveguide core layer by controlling the spacing of the discrete electrodes deposited on the polymer spacing layer, so that the complexity of the process is obviously reduced, and the yield is improved. The electro-optic overlapping factor of the modulator is also improved, the advantage that the electro-optic coefficient of lead zirconate titanate is large is fully utilized, and the modulator manufactured through the technology further has the advantages of being high in heterogeneous integration capacity, high in modulation efficiency and the like and has wide application prospects in the aspects of meeting high-speed large-capacity data transmission and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of planar optical waveguide electro-optic modulators and their manufacturing technologies, and particularly relates to a lead zirconate titanate high-speed electro-optic modulator based on a heterogeneous integrated waveguide and a manufacturing method thereof. Background Art

[0002] With the rapid development of technologies such as the Internet, big data, and cloud computing, the global data traffic has grown explosively, and the future demand for data transmission rates will continue to increase. In particular, the popularization of technologies such as artificial intelligence has put forward higher requirements for information interconnection technologies. As the core device of optical interconnection, the performance of electro-optic modulators directly affects the operating efficiency and data transmission capacity of data centers. In this regard, electro-optic modulators need to continuously improve their performance to achieve more efficient electro-optical signal conversion.

[0003] In order to achieve high-performance electro-optic modulators, various integrated electro-optic platforms have been reported and developed, mainly including silicon-based platforms, thin-film lithium niobate (LNOI) platforms, organic electro-optic polymer platforms, and lead zirconate titanate (PZT) platforms. Electro-optic modulators based on silicon-based platforms have become relatively mature after years of development. However, affected by high power consumption and slow modulation speed, they can no longer meet the current requirements for electro-optic modulators in the field of optical communication. Thin-film lithium niobate is currently the most widely used crystalline thin-film electro-optic material. However, the electro-optic coefficient limits the modulation efficiency of the modulator, and the complex waveguide fabrication etching process has slowed down its development process. In contrast, organic electro-optic polymers can be prepared by spin coating, providing a flexible and scalable alternative for integrated electro-optic modulation. However, the preparation of electro-optic polymer materials is complex and their stability is relatively low, resulting in the attenuation of the electro-optic performance of the materials, and still facing challenges in the field of electro-optic modulation.

[0004] PZT materials have a large electro-optic coefficient, which significantly improves the modulation efficiency of PZT electro-optic modulators. Therefore, they have received extensive attention and developed rapidly. However, in the current process of fabricating PZT waveguides, dry etching is required, which will greatly increase the process complexity and cost of the device. Summary of the Invention

[0005] In order to further improve the modulation efficiency of the modulator and simplify the process manufacturing process, the present invention proposes a lead zirconate titanate high-speed electro-optic modulator based on a heterogeneous integrated waveguide and a manufacturing method thereof.

[0006] In the present invention, a PZT thin film is used as the waveguide core layer, and a polymer spacer layer is directly spin-coated on the PZT thin film without etching the PZT. By controlling the spacing of the discrete electrodes deposited on the polymer spacer layer, the optical field is confined in the waveguide core layer, significantly reducing the complexity of the process and also improving the electro-optic overlap factor of the modulator, making full use of the advantage of the large electro-optic coefficient of lead zirconate titanate. The modulator fabricated by this process also has advantages such as strong heterogeneous integration ability and high modulation efficiency, and has broad application prospects for meeting high-speed and large-capacity data transmission and other aspects. In addition, the present invention uses a polymer material with a relatively high dielectric constant and a relatively low refractive index as the polymer spacer layer and the polymer upper cladding, making full use of the advantages of easy processing of the polymer material and compatibility with semiconductor processes, giving the device important practical application value.

[0007] As shown in the Figure 1 accompanying drawings, a lead zirconate titanate electro-optic phase modulator based on a heterogeneous integration waveguide structure according to the present invention comprises, from bottom to top, a silicon substrate 31, a silicon dioxide oxide layer 32 deposited on the upper surface of the substrate, an unetched lead zirconate titanate planar core layer 33 spin-coated on the upper surface of the silicon dioxide layer, a polymer spacer layer 34 spin-coated on the upper surface of the lead zirconate titanate planar core layer 33, discrete electrodes 1 evaporated on both sides of the upper surface of the polymer spacer layer 34, and a polymer upper cladding 35 spin-coated on the upper surfaces of the polymer spacer layer 34 and the discrete electrodes 1; the lengths a1 of the silicon substrate 31, the silicon dioxide oxide layer 32, the lead zirconate titanate planar core layer 33, the polymer spacer layer 34, the polymer upper cladding 35, and the discrete electrodes 1 are equal, being 4 - 8 mm, and the materials of the polymer spacer layer 34 and the polymer upper cladding 35 are the same.

[0008] As shown in the Figure 2 accompanying drawings (for the cross-section at the position of A - A' in the Figure 1 accompanying drawings), the thickness of the silicon substrate 31 is 480 - 520 μm, the thickness of the silicon dioxide oxide layer 32 is 1 - 5 μm, the thickness of the lead zirconate titanate planar core layer 33 is 0.25 - 0.35 μm, the thickness of the polymer spacer layer 34 is 0.1 - 0.3 μm, the thickness of the discrete electrodes 1 is 0.2 - 2 μm, and the thickness of the polymer upper cladding 35 above the discrete electrodes 1 is 0.5 - 5 μm; the two partial electrode structures in the discrete electrodes 1 are completely the same, the width b1 is 10 - 20 μm, and the spacing gap is 2 - 20 μm.

[0009] A method for preparing a lead zirconate titanate high-speed electro-optic modulator based on a heterogeneous integration waveguide according to the present invention, as Figure 3 shown in the accompanying drawings, comprises the following steps:

[0010] A: Cleaning of the lead zirconate titanate wafer

[0011] First, clean the surface of the lead zirconate titanate wafer (which can be directly purchased and consists of a silicon substrate 31, a silicon dioxide oxide layer 32, and a lead zirconate titanate flat core layer 33) 2 - 3 times in sequence with acetone, methanol, and isopropyl alcohol, and then dry it with nitrogen. Ensure the surface of the lead zirconate titanate wafer is clean to obtain the silicon substrate 31, the silicon dioxide oxide layer 32, and the lead zirconate titanate flat core layer 33. The thickness of the silicon substrate 31 is 480 - 520 μm, the thickness of the silicon dioxide oxide layer 32 is 1 - 5 μm, and the thickness of the lead zirconate titanate flat core layer 33 is 250 - 350 nm. B: Preparation of the polymer spacer layer

[0012] Adopt the spin - coating process to coat the surface of the clean lead zirconate titanate flat core layer 33 with a polymer spacer layer material (this polymer spacer layer material is a series of materials including polyimide (PI), polymethyl methacrylate (PMMA), SU - 8 2002, SU - 8 2005, etc., and the refractive index of the polymer spacer layer material is lower than that of the lead zirconate titanate flat core layer) at a rotational speed of 1000 - 8000 revolutions per minute. Bake it for 20 - 50 minutes under the condition of 100 - 500 °C and then cool it to room temperature to obtain a polymer spacer layer 34 with a thickness of 0.1 - 0.3 μm;

[0013] C: Preparation of discrete electrodes

[0014] Use the vacuum evaporation method to evaporate a metal electrode layer 2 (such as gold, aluminum, copper, etc.) with a thickness of 0.2 - 2 μm on the upper surface of the polymer spacer layer 34; then use the spin - coating process to spin - coat the photoresist BP212 on the surface of the metal electrode layer 2 at a rotational speed of 1000 - 8000 revolutions per minute to obtain a thickness of 1 - 10 μm for BP212; bake the device with spin - coated photoresist BP212 at a temperature of 50 - 300 °C for 10 - 50 minutes, and then cool it to room temperature for mask lithography; the structure of the mask is the same as the structure of the metal electrode to be prepared, and expose it under ultraviolet light with a wavelength of 300 - 500 nm for 10 - 20 s to expose the photoresist in the area other than the electrode; immerse the device in a NaOH solution with a mass concentration of 2 - 5‰ for 5 - 20 minutes to remove the exposed photoresist, then rinse it with deionized water, dry it with nitrogen, bake the device at 80 - 300 °C for 5 - 40 minutes and then cool it to room temperature; finally, expose the whole device for 2 - 5 s, and then immerse the device in ethanol for 1 - 8 minutes to obtain the discrete electrode 1 with the required structure; the two - part electrode structures in the discrete electrode 1 are exactly the same, the width b1 is 10 - 20 μm, and the spacing gap is 2 - 20 μm;

[0015] D. Preparation of the polymer upper cladding

[0016] Using a spin coating process, a polymer upper cladding material (the same material as the polymer spacer layer) is coated on the prepared discrete electrode 1 and the polymer spacer layer 34 at a rotation speed of 1000 - 6000 revolutions per minute, baked at 100 - 500 °C for 20 - 50 minutes, and then cooled to room temperature to obtain a polymer upper cladding 35 with a thickness of 0.5 - 5 μm, thus completing the preparation of the lead zirconate titanate high-speed electro-optic modulator based on the heterogeneous integrated waveguide.

[0017] Compared with the existing device structures and technologies, the beneficial effects of the present invention are as follows: The present invention uses an unetched lead zirconate titanate slab as the core layer, which has a larger electro-optic coefficient compared with lithium niobate. Therefore, the fabricated modulator has a larger modulation efficiency. Moreover, electro-optic polymers are used as the polymer spacer layer and the polymer upper cladding. Compared with silicon dioxide, electro-optic polymers have an electro-optic effect and a larger dielectric constant. When an external electric field is applied, the electric field is more evenly distributed between the signal electrode and the ground electrode, increasing the effective mode field area. At the same time, due to its smaller refractive index, the optical field can be effectively controlled within the core layer. In addition, the larger the dielectric constants of the polymer spacer layer and the polymer upper cladding, the greater the effect of the electric field on lead zirconate titanate, further improving the electro-optic phase modulation efficiency. Additionally, compared with the etched lead zirconate titanate electro-optic modulator, the manufacturing process flow is greatly simplified, the manufacturing difficulty of the device is reduced, and it has the advantages of low production cost and high efficiency. Brief Description of the Drawings

[0018] Figure 1 : Schematic structural diagram of the lead zirconate titanate high-speed electro-optic modulator based on the heterogeneous integrated waveguide;

[0019] Figure 2 : Figure 1 Schematic cross-sectional view of the modulator at A - A';

[0020] Figure 3 : Process flow chart for the preparation of the lead zirconate titanate high-speed electro-optic modulator based on the heterogeneous integrated waveguide;

[0021] Figure 4 (a): Figure 1 Optical field distribution diagram of the cross-section at A - A' in ;

[0022] Figure 4 (b): Figure 1 Electric field distribution diagram of the cross-section at A - A' in ;

[0023] Figure 5 (a): Variation curve of the half-wave voltage-length product of the electro-optic modulator with the thickness of the PZT slab core layer;

[0024] Figure 5 (b): Variation curve of the loss of the electro-optic modulator with the thickness of the PZT slab core layer;

[0025] Figure 5 (c): Curve of the product of the half-wave voltage and length of the electro-optic modulator varying with gap;

[0026] Figure 5 (d): Curve of the loss of the electro-optic modulator varying with gap;

[0027] Figure 6 : Curves of the reflection coefficient and transmission coefficient of the modulator varying with frequency.

[0028] As Figure 1 is a schematic three-dimensional structure diagram of a high-speed electro-optic modulator based on a heterogeneous integrated waveguide. The names of each part are: silicon substrate 31, silicon dioxide oxide layer 32 deposited on the upper surface of the substrate, unetched lead zirconate titanate flat core layer 33 deposited on the upper surface of the silicon dioxide oxide layer 32, polymer spacer layer 33 deposited on the upper surface of the lead zirconate titanate flat core layer 33, discrete electrode 1 evaporated on the upper surface of the polymer spacer layer 34, and polymer upper cladding 35 deposited on the upper surfaces of the polymer spacer layer 34 and discrete electrode 1.

[0029] As Figure 2 is a schematic diagram of the cross-section of the modulator ( Figure 1 the A-A' cross-section in

[0030] The names of each part are: silicon substrate 31, silicon dioxide oxide layer 32, lead zirconate titanate flat core layer 33, polymer spacer layer 34 spin-coated on lead zirconate titanate, discrete electrode 1, and polymer upper cladding 35. Figure 3 is a process flow chart for the preparation of a high-speed electro-optic modulator based on a heterogeneous integrated waveguide. The names of each part are: silicon substrate 31, silicon dioxide oxide layer 32, lead zirconate titanate flat core layer 33, polymer spacer layer 34, discrete electrode 1, and polymer upper cladding 35 prepared by a spin-coating process.

[0031] As Figure 4 (a) is a simulation diagram of the fundamental mode optical field distribution in the waveguide of the A-A' cross-section attached to a high-speed electro-optic modulator based on a heterogeneous integrated waveguide; It can be seen from the figure that the optical field is mostly distributed in the lead zirconate titanate flat core layer waveguide and the electro-optic polymer spacer layer. While ensuring the effective transmission of light, the overlapping area of the optical field and the electric field is increased, improving the modulation efficiency; Figure 1

[0032] Figure 4 As Figure 4 (b) is a simulation diagram of the fundamental mode optical field distribution in the waveguide of the A-A' cross-section attached to a high-speed electro-optic modulator based on a heterogeneous integrated waveguide; Figure 1Simulation diagram of the fundamental mode electric field distribution in the waveguide of the A-A' cross-section; the arrows on the surface in the figure represent the electric field distribution. It can be seen that the electric field distribution is uniform, and the electric field is relatively large at the boundaries of the electrode and the polymer upper cladding, the electrode and the polymer spacer layer, and the polymer spacer layer and lead zirconate titanate. According to Maxwell's equations, the polymer upper cladding and the polymer spacer layer with a relatively large relative permittivity at the dielectric boundary can increase the electric field strength inside the lead zirconate titanate waveguide, thereby improving the modulation efficiency.

[0033] As Figure 5 shown, the curves of the electro-optic modulation efficiency and loss of the high-speed electro-optic modulator based on the hetero-integrated waveguide structure with respect to the thickness of the lead zirconate titanate flat core layer and the gap are presented; among them, (a) is the relationship curve of the half-wave voltage length product of the electro-optic modulator in Example 1 with respect to the thickness of the lead zirconate titanate flat core layer. It can be seen that as the core layer thickness increases, the half-wave voltage length product of the modulator decreases, and the modulation efficiency becomes higher; (b) is the relationship curve of the loss of the electro-optic modulator in Example 1 with respect to the thickness of the lead zirconate titanate flat core layer. It can be seen that as the core layer thickness increases, the loss of the modulator decreases; (c) is the relationship curve of the half-wave voltage length product of the electro-optic modulator in Example 1 with respect to the metal electrode spacing gap. It can be seen that as the metal electrode spacing gap increases, the half-wave voltage length product of the modulator increases, and the modulation efficiency becomes lower; (d) is the relationship curve of the loss of the electro-optic modulator in Example 1 with respect to the metal electrode spacing gap. It can be seen that as the metal electrode spacing gap increases, the loss of the modulator decreases.

[0034] As Figure 6 shown, it is the modulator characteristic curve under the electrode structure of Example 1 of the high-speed electro-optic modulator based on the hetero-integrated waveguide structure; from the relationship curve of the transmission coefficient with respect to frequency, it can be seen that the transmission coefficient is lower in the high-frequency region and higher in the low-frequency region, and the bandwidth of the device can reach 100 GHz. From the relationship curve of the reflection parameter with respect to frequency, it can be seen that the reflection parameter is relatively small, below -20 dB. Detailed implementation manners

[0035] Example 1

[0036] The present invention will be further described below with reference to the accompanying drawings and examples.

[0037] As shown in the accompanying Figure 1As shown in the figure, a lead zirconate titanate electro-optic phase modulator based on a heterogeneous integrated waveguide structure according to the present invention is composed of a silicon substrate 31 from bottom to top, a silicon dioxide oxide layer 32 deposited on the upper surface of the substrate, an unetched lead zirconate titanate planar core layer 33 spin-coated on the upper surface of the silicon dioxide layer, a polymer spacer layer 34 spin-coated on the upper surface of the lead zirconate titanate planar core layer 33, discrete electrodes 1 evaporated on both sides of the upper surface of the polymer spacer layer 34, and a polymer upper cladding layer 35 deposited on the upper surfaces of the polymer spacer layer 34 and the discrete electrodes 1; the lengths a1 of the silicon substrate 31, the silicon dioxide oxide layer 32, the lead zirconate titanate planar core layer 33, the polymer spacer layer 34, the polymer upper cladding layer 35, and the discrete gold electrodes 1 are equal to 5 mm. The materials of the polymer spacer layer 34 and the polymer upper cladding layer 35 are the same and are a series of materials including polyimide (PI), polymethyl methacrylate (PMMA), SU-8 2002, SU-8 2005, etc. In this embodiment, polymethyl methacrylate (PMMA) is selected as the material of the polymer spacer layer 34 and the polymer upper cladding layer 35.

[0038] As shown in the attached Figure 2 figure (the cross-section at the A-A' position in the attached Figure 1 figure), the thickness of the silicon substrate 31 is 500 μm, the thickness of the silicon dioxide oxide layer 32 is 2 μm, the thickness of the lead zirconate titanate planar core layer 33 is 0.3 μm, the thickness of the polymer spacer layer 34 is 0.2 μm, the thickness of the discrete electrodes 1 is 0.8 μm, and the thickness of the polymer upper cladding layer 35 above the discrete electrodes 1 is 2 μm. The two parts of the discrete electrodes 1 are exactly the same, the width b1 is 20 μm, and the distance gap between the two parts is 5 μm.

[0039] Under the above parameter conditions, through the simulation software Comsol Multiphysics calculation, the phase modulation efficiency of the modulator can be obtained as 0.6 V·cm, and the loss is 0.6 dB / mm. The HFSS software is used to simulate the radio frequency situation of the modulator. Among them, the transmission parameters (S 12 and S 21 ) are relatively large, and the reflection parameters (S 11 and S 22 ) are relatively small. The results show that in a relatively wide frequency range of 0-100 GHz, the traveling wave electrodes of this structure have a small reflectivity and a large transmittance.

[0040] The preparation method of the high-speed electro-optic modulator based on the heterogeneous integrated waveguide according to the present invention is as follows:

[0041] (1) Cleaning of the lead zirconate titanate wafer: First, the surface 33 of the lead zirconate titanate wafer is cleaned twice with acetone, methanol, and isopropyl alcohol in sequence, and dried with nitrogen to determine that the surface of the lead zirconate titanate is clean; the silicon substrate 31, the silicon dioxide oxide layer 32, and the lead zirconate titanate planar core layer 33 are obtained;

[0042] (2) Preparation of the polymer spacer layer: Using the spin-coating process, coat the polymer material on the surface of the clean lead zirconate titanate flat core layer 33 at a rotation speed of 8000 revolutions per minute. Bake it at 120 °C for 20 minutes and then cool it down to room temperature to obtain a polymer spacer layer 34 with a thickness of 0.2 μm;

[0043] (3) Preparation of the discrete electrodes: Use the vacuum evaporation method to evaporate a 0.8-μm-thick gold electrode layer 2 on the polymer spacer layer 34. Use the spin-coating process to coat the photoresist BP212 on the surface of the gold electrode layer 2 at a rotation speed of 2500 revolutions per minute to obtain a thickness of 2 μm for BP212; Heat the device with the spin-coated photoresist BP212 and bake it at 150 °C for 20 minutes, then cool it down to room temperature for photolithography; The mask has the same structure as the heating electrode to be prepared. Expose it under ultraviolet light with a wavelength of 365 nm for 15 s so that the photoresist in the area other than the electrode is exposed; Immerse the device in a 5‰ NaOH solution by mass for 5 minutes to remove the exposed photoresist, then rinse it with deionized water, dry it with nitrogen, and bake the device at 95 °C for 10 minutes and cool it down to room temperature; Then expose the entire substrate for 12 s, and then immerse the device in ethanol for 1 minute to obtain the required discrete electrodes 1;

[0044] (4) Preparation of the polymer upper cladding: Use the spin-coating process to coat the polymer upper cladding material on the prepared discrete electrodes 1 and the polymer spacer layer 34 at a rotation speed of 4000 revolutions per minute. Bake it at 120 °C for 20 minutes and then cool it down to room temperature to obtain a polymer upper cladding 35 with a thickness of 2 μm.

[0045] In this way, a high-speed electro-optic modulator based on a heterogeneous integrated waveguide that meets the requirements is prepared. It should be noted that although this patent document contains descriptions of many details, it should not be construed as a limitation on the scope of any disclosed technology or what may be claimed, but rather as a description of the features specific to a particular embodiment of the disclosed technology. The present invention can also have many variations, such as using electro-optic materials such as barium titanate and lithium niobate. Those skilled in the art, based on what is clearly disclosed in the present invention or obtained without any objection according to the written description of the document, fall within the scope protected by this patent.

Claims

1. A lead zirconate titanate electro-optic phase modulator based on a heterogeneous integrated waveguide structure, characterized in that: The invention is composed of, from bottom to top, a silicon substrate (31), a silicon dioxide oxide layer (32) deposited on the upper surface of the substrate, an unetched lead zirconate titanate flat core layer (33) spin-coated on the upper surface of the silicon dioxide layer, a polymer spacer layer (34) spin-coated on the upper surface of the lead zirconate titanate flat core layer (33), discrete electrodes (1) evaporated on both sides of the upper surface of the polymer spacer layer (34), and a polymer upper cladding layer (35) spin-coated on the upper surfaces of the polymer spacer layer (34) and the discrete electrodes (1); the lengths a1 of the silicon substrate (31), the silicon dioxide oxide layer (32), the lead zirconate titanate flat core layer (33), the polymer spacer layer (34), the polymer upper cladding layer (35), and the discrete electrodes (1) are equal, and the materials of the polymer spacer layer (34) and the polymer upper cladding layer (35) are the same.

2. The lead zirconate titanate electro-optic phase modulator based on a heterogeneous integrated waveguide structure according to claim 1, characterized in that: The length a1 of the silicon substrate (31), the silicon dioxide oxide layer (32), the lead zirconate titanate flat core layer (33), the polymer spacer layer (34), the polymer upper cladding layer (35), and the discrete electrode (1) is equal to 4 to 8 mm, the thickness of the silicon substrate (31) is 480 to 520 μm, the thickness of the silicon dioxide oxide layer (32) is 1 to 5 μm, the thickness of the lead zirconate titanate flat core layer (33) is 0.25 to 0.35 μm, and the thickness of the polymer spacer layer (34) is 0.1 to 0.3 μm; the thickness of the discrete electrode (1) is 0.2 to 2 μm, and the thickness of the polymer upper cladding layer (35) on the discrete electrode (1) is 0.5 to 5 μm; the two parts of the electrode structure in the discrete electrode (1) are completely the same, the width b1 is 10 to 20 μm, and the gap is 2 to 20 μm.

3. The lead zirconate titanate electro-optic phase modulator based on a heterogeneous integrated waveguide structure according to claim 1, characterized in that: The materials of the polymer spacer layer (34) and the polymer upper cladding layer (35) are polyimide, polymethyl methacrylate, SU-8 2002 or SU-8 2005.

4. A method for preparing a lead zirconate titanate electro-optic phase modulator based on a heterogeneous integrated waveguide structure according to any one of claims 1 to 3, wherein the steps are as follows: A: Lead zirconate titanate wafer cleaning First, the surface of the lead zirconate titanate wafer is cleaned 2 to 3 times with acetone, methanol, and isopropanol in sequence, and then dried with nitrogen to ensure that the surface of the lead zirconate titanate wafer is clean, thereby obtaining a silicon substrate (31), a silicon dioxide oxide layer (32), and a lead zirconate titanate flat core layer (33); B: Preparation of polymer spacer layer The polymer spacer layer material is coated on the surface of the clean lead zirconate titanate flat core layer (33) by spin coating process, the rotation speed is 1000-8000 rpm, baked at 100-500° C. for 20-50 minutes and then cooled to room temperature to obtain the polymer spacer layer (34); C: Preparation of discrete electrodes A metal electrode layer (2) is evaporated on the upper surface of a polymer spacer layer (34) by a vacuum evaporation method; then a photoresist BP212 is spin-coated on the surface of the metal electrode layer (2) by a spin coating process at a rotation speed of 1000 to 8000 revolutions per minute, so that the thickness of the BP212 is 1 to 10 μm; the device spin-coated with the photoresist BP212 is baked at a temperature of 50 to 300° C. for 10 to 50 minutes, and then cooled to room temperature for mask photolithography; the structure of the mask is the same as the structure of the metal electrode to be prepared , exposing the device to ultraviolet light with a wavelength of 300 to 500 nm for 10 to 20 seconds to expose the photoresist in the area other than the electrode; placing the device in a NaOH solution with a mass concentration of 2 to 5‰ for 5 to 20 minutes to remove the exposed photoresist, then rinsing it with deionized water and drying it with nitrogen, baking the device at 80 to 300° C. for 5 to 40 minutes and then cooling it to room temperature; finally, exposing the entire device for 2 to 5 seconds, and then immersing the device in ethanol for 1 to 8 minutes to obtain discrete electrodes (1) of the required structure; D. Preparation of polymer upper cladding The polymer upper cladding material is coated on the prepared discrete electrode (1) and the polymer spacer layer (34) by a spin coating process at a rotation speed of 1000 to 6000 rpm, baked at 100 to 500° C. for 20 to 50 minutes and then cooled to room temperature to obtain a polymer upper cladding (35), thereby completing the preparation of the lead zirconate titanate high-speed electro-optic modulator based on heterogeneous integrated waveguide.

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